H-337: restore Web widget reply visibility (#64)

* H-337: restore widget reply delivery

* H-337: harden widget conversation ownership

---------

Co-authored-by: Rogee <rogee@ipao.vip>

backend/internal/database/widget_conversation_migration_test.go

@@ -0,0 +1,72 @@
+package database
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"gorm.io/driver/sqlite"
+	"gorm.io/gorm"
+)
+
+const widgetConversationMigrationBaseline = `
+CREATE TABLE inboxes (id INTEGER PRIMARY KEY, channel_type TEXT NOT NULL);
+CREATE TABLE contact_inboxes (id INTEGER PRIMARY KEY, contact_id INTEGER NOT NULL, inbox_id INTEGER NOT NULL);
+CREATE TABLE conversations (id INTEGER PRIMARY KEY, contact_id INTEGER NOT NULL, inbox_id INTEGER NOT NULL, contact_inbox_id INTEGER);
+`
+
+func TestWidgetConversationContactInboxMigrationRoundTrip(t *testing.T) {
+	dbPath := filepath.Join(t.TempDir(), "widget-conversations.db")
+	dbURL := "sqlite3://" + dbPath
+	db, err := gorm.Open(sqlite.Open(dbPath), &gorm.Config{})
+	require.NoError(t, err)
+	sqlDB, err := db.DB()
+	require.NoError(t, err)
+	sqlDB.SetMaxOpenConns(1)
+	t.Cleanup(func() { _ = sqlDB.Close() })
+	require.NoError(t, db.Exec(widgetConversationMigrationBaseline).Error)
+	require.NoError(t, db.Exec(`
+INSERT INTO inboxes VALUES (1, 'web_widget'), (2, 'api');
+INSERT INTO contact_inboxes VALUES (1, 10, 1), (2, 20, 1), (3, 20, 1), (4, 30, 1);
+INSERT INTO conversations VALUES
+  (1, 10, 1, NULL),
+  (2, 20, 1, NULL),
+  (3, 30, 1, 4),
+  (4, 10, 2, NULL);
+`).Error)
+
+	migrations := t.TempDir()
+	for _, direction := range []string{"up", "down"} {
+		require.NoError(t, os.WriteFile(filepath.Join(migrations, "000081_baseline."+direction+".sql"), []byte("SELECT 1;"), 0o600))
+		name := "000082_backfill_widget_conversation_contact_inboxes." + direction + ".sql"
+		data, readErr := os.ReadFile(filepath.Join("..", "..", "migrations", name))
+		require.NoError(t, readErr)
+		require.NoError(t, os.WriteFile(filepath.Join(migrations, name), data, 0o600))
+	}
+	require.NoError(t, ForceVersion(dbURL, migrations, 81))
+	require.NoError(t, MigrateSteps(dbURL, migrations, 1))
+
+	var bindings []struct {
+		ID             uint
+		ContactInboxID *uint
+	}
+	require.NoError(t, db.Raw("SELECT id, contact_inbox_id FROM conversations ORDER BY id").Scan(&bindings).Error)
+	require.Len(t, bindings, 4)
+	require.NotNil(t, bindings[0].ContactInboxID)
+	assert.Equal(t, uint(1), *bindings[0].ContactInboxID)
+	assert.Nil(t, bindings[1].ContactInboxID)
+	require.NotNil(t, bindings[2].ContactInboxID)
+	assert.Equal(t, uint(4), *bindings[2].ContactInboxID)
+	assert.Nil(t, bindings[3].ContactInboxID)
+
+	require.NoError(t, MigrateSteps(dbURL, migrations, -1))
+	require.NoError(t, db.Raw("SELECT id, contact_inbox_id FROM conversations ORDER BY id").Scan(&bindings).Error)
+	assert.Nil(t, bindings[0].ContactInboxID)
+	assert.Nil(t, bindings[1].ContactInboxID)
+	require.NotNil(t, bindings[2].ContactInboxID)
+	assert.Equal(t, uint(4), *bindings[2].ContactInboxID)
+	assert.Nil(t, bindings[3].ContactInboxID)
+	assert.False(t, db.Migrator().HasTable("widget_conversation_contact_inbox_backfills"))
+}